Nail enamels are traditionally anhydrous products. If any water is present at all in the traditional enamel it is usually due to slight contamination of the raw materials during manufacture or storage.
Proper hydration of human nails is very important to nail physiology. When nails become dehydrated, for example due to harsh environmental conditions or the use of nail enamel removers, they frequently crack, split, or peel more readily. There is thus a need for nail enamels which do not dehydrate the nails.
U.S Pat. No. 4,402,935 discloses a nail polish composition which contains water and urea to impart moisture to the nail. Polyvinyl butyral resin is used to harden the composition and increase adhesion to the nail. Urea is potentially irritating to skin and surrounding tissues, however, so it is not ideally suited to imparting moisture to the nail.
U.S. Pat. No. 3,034,965 discloses a nail treatment composition containing water, however the composition is not a nail lacquer but functions instead as a base which is used to treat nails prior to the application of polish. It has no coating or lacquer phase.
U.S. Pat. No. 4,158,053 discloses aqueous emulsion polymers suitable for nail lacquers which are formed as a result of polymerization of certain monomers in an aqueous medium. The polymerization of monomers in aqueous media results in a very slow drying lacquer since the hardening i.e. polymerization, depends on the evaporation of water rather than the much more rapid evaporation of volatile solvents. Furthermore, this preparation does not contain nitrocellulose which has a great affinity for water.
U.S. Pat. No. 4,897,261 is directed to a nail enamel composition containing water and a water soluble or oil soluble polymer in addition to the lacquer phase.